1. Field of the Invention
The present invention relates generally to production of plasmas.
2. Description of the Related Art
High-temperature, high-pressure plasmas have many potential uses but can be hard to control. For example, arc welding uses thermal plasma arcs at around 1 Atm pressure and a few thousand degrees K temperature. In arc welding the plasma arc is very short and tends to walk on the node surface. Attempts to stabilize very high-temperature plasma arcs for use in nuclear fusion have not yet succeeded in a commercial way, despite decades of research. Large magnetic confinement devices and laser compression of pellets (inertial confinement), such as at the National Ignition Facility (NIF), are still searching for a plasma having sufficient density, temperature, and lifetime to produce enough fusion of deuterium and tritium (D and T) to be commercially viable. The root problem is that dense, high-temperature, high-pressure plasmas develop instabilities in a very short time that cause plasma growth in unpredictable directions.
A measure of plasma stability, temperature, and density is nTt, where n is number density of molecules and atoms in the plasma, T is plasma temperature, and t is lifetime of the stable plasma. Plasmas having large nTt are hard to obtain.
A. A. Sivkov reported formation of a plasma arc in “Hybrid Electromagnetic System for Acceleration Solids,” Journal of Applied Mechanics and Technical Physics, Vol. 42, No. 1 (2001), pp. 1-9. The plasma arc in Sivkov was formed by the thermally induced explosion of small wires and by a longitudinal magnetic field that formed the debris through which the current passed into an arc and plasma bridge. In Sivkov, a plasma column to return the current was formed by electromagnetic processes some time after the wires exploded.